Evaluation of Coagulation Functional Parameters of Chrysophyllum albidum Seeds in Turbidity Removal from Surface Water
1 * Idiok, U.T. and 2Udemba, J.N.
1Department of Civil Engineering, Topfaith University, Mkpatak, Akwa Ibom State, Nigeria.
2Department of Civil Engineering, Chukwuemeka Odumegwu Ojukwu University, Uli, Nigeria.
DOI: 10.36108/laujoces/6202.61.0280
Abstract
Coagulation–flocculation is essential for removing turbidity-causing colloids from surface water yet concerns over conventional inorganic coagulants have driven interest in sustainable alternatives. This study evaluates the coagulation functional parameters of Chrysophyllum albidum seed in turbidity removal from surface water. The effects of pH, coagulant dosage, and settling time on removal efficiency and coagulation kinetics were examined. Surface water samples were collected from River Ezu, Anambra State, Nigeria, while Chrysophyllum albidum seeds were processed and extracted using ethanol solvent extraction prior to jar test coagulation experiments Jar test experiments were conducted at varying pH values (3–9), coagulant dosages (0.8–2.2 g/L) and settling times (10–50 min). Perikinetic data generated were fitted to specific kinetic models for the determination of coag-flocculation reaction order , coag-flocculation rate constant K, and coagulation period τ1/2. The best coag-flocculation activity was recorded at dosage of 1.0g/L, pH of 3, yielding over 75% turbidity removal, with coagulation rate constant K = 7.4733×10- 4m3/kg.s, and coagulation period τ1/2 = 4.58 Secs, while the least was recorded at a dosage of 2.2g/L (K = 1.1129×10-5S-1 and τ1/2 = 307.12 Secs). Kinetic analysis revealed low coagulation periods, high collision efficiencies, and maximum coagulation rate constants at the optimal dosage. The coag–flocculation process predominantly followed second-order reaction kinetics (>83%), indicating that particle removal was governed mainly by inter-particle collisions. Chrysophyllum albidum seed extract demonstrated strong potential as an effective green coagulant for surface water treatment. Despite the requirement for acidic operating conditions, its high turbidity removal efficiency and favorable coagulation kinetics support its applicability as a low-cost, biodegradable, and environmentally sustainable alternative to conventional chemical coagulants.
Keywords: Coag-flocculation, Kinetics, Turbidty, Chrysophyllum albidum, Coagulation constants